Staff Sergeant Calvin Gibbs has been sentenced to life in prison for a series of massacres he was involved with between January and May of last year. Because his attorney waged for a sentencing with the possibility of parole, Gibbs could be freed in as little as ten years.

A military tribunal found the soldier guilty of 15 counts in all, including three charges of premeditated murder.

According to testimonies in the courtroom, Gibbs had executed Afghanis while serving overseas and then raided their remains for proof. Additionally, he posed with the deceased. When quizzed by his attorney about why he would do so, Gibbs replied, "People wanted to prove they were there.”

"He is the savage, not the innocent Afghans he murdered. It is monstrous. What kind of savagery does it take to do this? To cut a finger off a victim and show it to people? This is a savage being,” prosecutor Maj. Andre Leblanc said at the sentencing.

Gibbs was the highest-ranked soldier among the 5th Stryker Brigade, whose other members have been faced with charges related to the thrill kills. In a taped confession from May 2010, fellow servicemen told investigations that Gibbs was a “crazy” sergeant and masterminded the assaults.

"He just really doesn't have any problems with fucking killing these people," Jeremy Morlock said at the time from Kadahar.

"And so we identify a guy. Gibbs makes a comment, like, you know, you guys wanna wax this guy or what?" Morlock said." And you know, he set it up, like, he grabbed the dude."

Corporal Morlock was detailed about describing some of the events when speaking with investigators ladt year. At one point on the tape, Morlock says, "He pulled out one of his grenades, an American grenade, you know, popped it, throws it, tells me where to go to whack this guy, kill this guy, kill this guy.”

“When you got a squad leader bringing you into that, that type of real, that mindset, and he believes that you're on board with that, there's definitely no way you wanted him to think otherwise,” added Morlock. He told investigators he felt threatened by Gibbs, who would warn him that “people disappear on the battlefield all the time.”

For three counts of premeditated murder, Morlock was sentenced earlier this year to 24 years behind bars.

In addition to killing civilians, prosecutors also attested that Gibbs had placed weapons on the deceased, including a Russian grenade during one incident, to make the assaults carried out by his own team look like they were aimed at insurgents.

"Selling a fake engagement as a real engagement, that's what they were doing," prosecutor Maj. Robert Stelle said during the hearing.

Prosecutors lashed-out at Gibbs throughout the week-long trial, quick to call him out for his brutal behavior.

"Sergeant Gibbs had a charisma, he had a 'follow me' personality," Maj. Stelle said during Wednesday’s closing arguments, "But it was all a bunch of crap. He had his own mission: murder and depravity."

Gibbs maintained throughout the trial that he was innocent of murdering civilians but did admit to collecting his morbid trophies. Prosecutors, however, lobbied that he executed three unarmed civilians in Afghanistan. A five-panel jury deliberated for four hours before coming to their guilty verdict.

Three others from his unit have already pled guilty to related charges.